St. Barbary, the patron saint of arsenals and powder magazines. Her father delivered her up to Martian, governor of Nicomedia, for being a Christian. After she had been subjected to the most cruel tortures, her unnatural father was about to strike off her head, when a lightning flash laid him dead at her feet. Hence, those who invoke saints select St. Barbary in thunderstorms. (See Barbe.)
ldquo;O, how it yearned my heart when I beheld In London streets that coronation day. When Bolingbroke rode on roan Barbary! That horse that thou [Rich. II.] so often hast bestrid, That horse that I so carefully have dressed.
Shakespeare: Richard II, v. 5.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Barbary from Fact Monster: